Malignant transformation of the mature ovarian teratoma into early-stage ovarian adenocarcinoma: A case report with literature review

Although mature ovarian teratoma (MOT) is one of the most commonly detected benign tumours worldwide, its malignant transformation is rare. This article presents a case of a 47-year-old woman, operated on for emergency reasons due to a giant painful ovarian tumour, showing preoperatively no signs of malignancy. Surprisingly, a pathological report showed MOT coexisting with an early-stage ovarian adenocarcinoma developing as an endophytic papilloma. Interestingly, a previously unclassified mutation variant in exon 18 of BRCA2 (NM_000059.3):c. 8167 G>A (p.Asp2723Asn) was detected in ovarian adenocarcinoma. A brief literature review has been presented discussing the clinicopathological features of MOT being associated with malignant transformation into an early-stage ovarian adenocarcinoma.